Feeding mechanism for rock drills



Jan. 10, 1939.

J. C. CURTIS FEEDING MECHANISM FOR ROCK DRILLS Filed April 2l, 1956 3Sheets-Sheet 1 Jan. 10,1939, J. C. CURTIS 2,143,105

FEEDING MECHANISM FOR ROCK DRILLSv I l 3 Sheets-Sheet 2 Filed April 2l,1936 ABY- I l ATroRNEY Jan. l0, 1939. .1. c. CURTIS FEEDING MECHANISMFOR ROCKl DRILLS 3 Sheets-shet' Filed April 2l, 1936 Jo/-fA/cz caff/5INVENTOR ATTORNEY Patented Jan. 10, 1939 UiTE STATES PATENT OFFICEFEEDING MECHANSM FOR RQCK DRILLS Application April 21,

7 Claims.

This invention relates broadly to rock drills, but more particularly toa feeding mechanism for rock drills of the percussive type.

One object of this invention is to produce a feeding mechanism for rockdrills susceptible of manual and automatic operation for impartingfeeding motion to the drill.

Another object of this invention is to provide a feeding mechanism forrock drills with means in readily operable for selectively transformingthe feeding mechanism in a manually or automatically operated mechanism.

Another object of this invention is to provide a normally automaticallyoperated feeding device for rock drills with means shaped and disposedin the most common manner whereby manual feeding motion may be impartedto the drill irrespective of said mechanism.

Other objects and advantages more or less an- ;t cillary to theforegoing and the manner in which the various objects are attained,reside in the speciiic construction and aggroupment of the elementspeculiar to this structure, as will become apparent from a more completeexamination of this specification, in the claims of which there areassembled certain specific combinations of parts and specificconstructions indicative of the scope and spirit of the invention.

In the drawings:

.do Fig. 1 is a longitudinal view partly in section illustrating a rockdrill having the improved feeding mechanism applied thereto, the rockdrill being shown positioned atone extreme end of its travel.

Fig. 2 is a view similar to Fig. l illustrating the rock drill inanother position.

Fig. 3 is an enlarged longitudinal sectional View of the connectionbetween the drill and the feeding mechanism.

Fig. 4 is an enlarged cross sectional View taken in a plane indicated byline d--fi in Fig. l.

Fig. 5 is an enlarged cross sectional view taken in a plane indicated byline 5 5 in Fig. 1.

Fig. 6 is a view similar to Fig. 5 illustrating some of the parts indierent position.

Fig. 7 is an enlarged sectional View taken in a plane indicated by line1 1 in Fig. 5.

Fig. 8 is a sectional View tak-en in a plane indicated by line 8 3 -inFig. 5.

Fig. 9 is a side elevational view of the part shown in Fig. 8.

Figs. 10, 1l and l2 are cross sectional views taken in a plane indicatedby line Iii-lil in Fig. 5 and looking in the direction of the arrowsterminating the line. lFor purpose of illustration,

ne at) 1936, Serial No. 75,593

(Cl. Z55-45) the handle located at the extreme left end of Fig. 5 hasbeen shown in dotted lines in these three gures.

Fig. 13 is a longitudinal sectional View taken in a plane indicated byline 1,3-13 in Fig. 5 illus- 5 trating the left end portion of themechanism shown in Fig. 1.

Fig. 14 is an enlarged cross sectional view taken in a plane indicatedby line it--M in Fig. 2.

Fig. 15 is an enlarged sectional View taken in a plane indicated by lineIii-i5 in Fig. 10.

Referring to the drawings in which like symbols designate correspondingparts throughout the several views, It represents a percussive rockdrill or drilling motor having a piston (not shown) reciprocable thereinfor imparting blows to a drill steel l1 reciprocably mounted within thefront housing of the rock drill. The motive fluid may be admitted intothe motor ESS through a connection i8 forming a part of the back head19.

The lower -wall of the motor i6 extends laterally to form twolongitudinally disposed guides 2li, which are slidably guided within thecorresponding guideways 2| formed with the upper portion of a tube orshell 22. This shell is located under the motor l5 to support the same,and has its lower portion also formed with guides 23 slidably guidedwithin the guideways 24 of a stationary support 25. For mountingpurpose, this support has a conical portion 25 depending therefrom. Thelength of the support 25 is substantially equal to one half the lengthof the shell 22, which is slidable relatively thereto with the motor ISslidable on the shell.

Located within the right end of the shell 22 in Fig. 1, hereinafterdenoted as the front end of the mechanism, there is a sprocket wheel 21rotatably 'mounted on a shaft or bolt 28 transversally disposed throughthe shell 22. The position of this shaft is such that the sprocket wheel21 protrudes f below the shell through a short slot 29 provided in thebottom of the shell.

Mounted within the rear end of the shell 22, there is a housing 30secured therein by bolts 3l extending through the housing and shell.Transversally disposed within the housing 33, there is a shaft 32 whichis formed with an integral handle 33 extending outside of the housingfor rotary movement within a vertical plane located on the left handside of the assembly when viewed from the left end in Fig. l. Disposedthrough the shaft 32 adjacent the handle 33, there is a cross pin 34 ofa length substantially equal to the bore 35 of a cover or cap 36 securedto the side of the housing 3l) by bolts 31. Clamped between the cap V36and u the adjacent side wall of the housing 36, there is the partlyannular shoulder 33 of a sleeve The side wall of the sleeve 39 is partlymachined to form two diametrically opposed substantially V- shaped cams48 with the bottom thereof arcuated as at 4I to accommodate the pin 34,while the top ends thereof are recessed as at 42 to form stops and locksfor the pin 34.

Journaled on the shaft 32, there is a sleeve 43 which extends beyond theinner end of the shaft. This sleeve has its right end portion in Fig. 5slotted to slidably receive the cross pin 44 of a short shaft 45, whichis slidably mounted within the sleeve 43 in abutting engagement with theshaft 32. The cross pin 44 carries a clutch member 46 slidably mountedon the sleeve 43, and formed with splines 41. This clutch member isconstantly urged toward the left in Fig. 5 by the effort of acompression spring 45, which is seated on a washer 49, the latter beingsecured to the sleeve 43 by a spring clip 50.

The splines 41 of the clutch member 46 are capable of operativeengagement with the corresponding splines 5I of a worm gear 52, which isrotatably mounted within the housing Meshing with the teeth of the wormgear 52, there is a Worm 53 disposed longitudinally within the housing38 and rotatable by a crank handle 54, which is secured thereto by abolt 55.

Intermediate its ends, the sleeve 43 has secured thereon by a. key 55, asprocket wheel 51, which is located between two spacers 58 and 59, theformer having the worm wheel 52 rotatably mounted thereon. The housing35 has an arcuated wall 60 extending behind the sprocket wheel 51 asshown in Fig. 13, while ahead of the sprocket wheel the housing isprovided with two substantially rectangular openings GI and 82, thepurpose of which will be explained later.

Adjacent the cap 36, there is secured on the sleeve 43 by a key 63 adisk E4, which has its peripheral wall formed with teeth 65. Pivotallymounted within the wall of the housing 3i) adjacent the peripheral wallof the disk 64, there are two sets of pawls 55 and 61. In the presentconstruction, there are shown six pawls 53, which are located withrespect to the teeth 55 for alternative operative engagement with oneside thereof, and two pawls 81 capable of alternative engagement withthe other side of the teeth 55. Each of these pawls has a torsion spring68 associated therewith for constantly urging the pawls in engagementwith the teeth 65 of the disk 54. The pawls 66 and 31 are somewhatlonger than the Width of the disk 64, and extend beyond the latter overa cam plate 69, which is rotatably mounted between the disk 64 and thecover 36. The normal outside diameter of this plate is substantiallyequal to or somewhat greater than the outside diameter of the disk 64,and has a hub like portion rotatably mounted within the sleeve 33. Thishub 10 is also slotted to receive the cross pin 34 by which the rotationof the shaft 32 is transmitted to the cam plate 68, while the sleeve 39is locked against rotation to the cover 35 by a small lock pin 1I. Theperipheral wall of the cam plate 69 is formed with two diametricallyopposed cut away portions or notches 12 of a sufficient length foraccommodating the pawls 66.

Depending from the drilling motor I5 into the shell 22, there is alongitudinally apertured lug 13 having a sleeve 14 extendingtherethrough and formed with a collar 15 engaging one side of the lug.The collar has a flat portion 16 engaging the lower wall of the motor I6to lock the sleeve against rotation relative to the lug. The other endof the sleeve 14 is threaded to receive a nut 11 engaging the other sideof the lug. Within the sleeve 14, there is a longitudinally disposed pin18 having a nut 19 secured to the inner end thereof, and engaging arubber buffer 8U located between the nuts 11 and 19. The pin 18 extendsthrough the nut 11 where it is fastened thereto by a cross pin 8 I, tothe end of a chain 82. From the apertured lug, the chain 82 extendsrearwardly through the rectangular opening 8l formed Within the housing30, where it passes over the sprocket wheel 51, and therefrom it extendsforwardly toward the support 25, through the rectangular opening 62. Theother end of the chain is finally secured to the rea-r end of thesupport 25 by a bolt 83, which is adjustable longitudinally by nuts 84within an apertured lug 85 depending from the support 25.

Secured by a cross pin 86 to the sleeve 14 mounted within the aperturedlug 13 of the motor I6, there is the end of another chain 81, whichchain extends forwardly over the sprocket Wheel 21 mounted Within thefront end of the shell 22. From the sprocket wheel 21, the chain 81extends rearwardly toward the support 25, Where its other end is aflixedto the front end of the support by a cross pin 88.

From the foregoing, it will be noticed that the portion of the chains 82and 81 extending from the drilling motor lug 13 to their respectivesprocket Wheel, is located inside of the shell 22, while the portionthereof extending from the sprocket Wheels to the support 25, is locatedunder the shell 22.

In the operation of the mechanism, let us assume that the handle orlever 33 of the shaft 32 is positioned as shown by dotted lines in Fig.10. In this instance, the cross pin 34 of the shaft 32 is engaging thebottom 4I of the cam 48, thus permitting the short shaft 45 to assumethe position shown in Fig. 5 and thereby causing the engagement of theclutch member 46 with the corresponding splines 5| of the worm gear 52.Due to the effort of the compression spring 48 on the clutch member 46,the short shaft 45 is constantly urged toward the left in Fig. 5, thusexerting pressure on the end of the shaft 32 for maintaining its crosspin 34 in forcible engagement with the cam 4I). When the parts arepositioned as shown in Fig. 5, it will be understood that the sprocketwheel 51 is normally locked against rotation due to the interengagementof gear 52 and worm 53, preventing thereby the accidental slidablemovement of the motor I6 relative to the shell 22 and support 25. ItWill also be understood that manual rotation may be imparted to the wormgear 52 by the worm 53 and crank handle 54, which rotation istransmitted to the sleeve 43 by the cross pin 44. From the sleeve 43 therotation is transmitted to the sprocket wheel 51 through the key 55, andto the disk 64 through the key 63. In this instance, the plate 69 whichis connected to the momentarily stationary shaft 32 by the cross pin 34is held in the position shown in Fig. 10. In this position the normalperipheral wall of the disk engages the end of the pawls 66 and 61 whichprotrudes from the disk 64, thus preventing the engagement of the pawlswith the teeth 65 of the disk, and thereby permitting the free rotationof the sprocket wheel 51 which is manually imparted thereto by rotatingthe crank handle 54. Since the sprocket wheels 21 and 51 are carried bythe shell 22, and that the chains passing over these sprocket wheelshave one end ference.

axed to the support and the other end to the motor, it will beunderstood that the rotation of the sprocket wheel l will cause thelongitudinal movement of the shell and motor relative to the support,the drilling motor moving in the same direction as the drill but at adouble rate of speed, its possible range of travel being equal to thecombined range of travel of the motor on the shell and of the shell onthe. support.

When it is desired to change thefeeding mechanism from a manual to anautomatic operation, it is only necessary to shift the lever or handle33 in either the position shown in Fig. l1 or Fig, 12. During therotation of the handle 33 from the position shown in Fig. l) to the oneshown in Fig. 11 for instance, the cross pin 3 engaging the cam 40 willmove from the bottom f3! into the recesses 42, thus causing thelongitudinal movement of the shaft 32 and the consequential slidablemovement toward the right in Fig. 5, of the short shaft 45. The crosspin 44, carried by the short shaft i5, will cause the clutch member d5to move out ci engagement with the worm gear 52 as shown in Fig. 6. Whenthe handle 33 is positioned as shown in dotted line in Fig. ll, theplate 69 being rotated by the cross pin 35 will alsobe positioned asshown in this last ligure, that is with the notches i2 in opposition tothe pawls t6, thus permitting the operative engagement of the pawls withthe teeth S5 of the disk 64.

During the operation of the drilling motor i6, the reversal of thepiston strokes therein will impart jars or forward and rearward movementto the motor i 5, thus normally imparting oscillatory motion to thesprocket wheel 5l. When the plate 69 is positioned as shown in Fig. ll,the pawls @t engaging one side of the teeth 65, will prevent therotation of the disk 54, sleeve 43 and sprocket wheel 5i in a clockwisedirection in Fig. 11, thus preventing the rearward movement of the motorI 6. During the forward movement of the motor, the sprocket wheel 5i anddisk 64 will rotate in a counterclockwise direction in Fig. 11, whichrotation is not checked by the pawls E6 since the latter will simplyride the teeth 65 without inter- From the foregoing, it will beunderstood that when the handle 33 is positioned as shown in Fig. l1,the drilling motor i5, dueto the jars imparted thereto, is capable ofstep by step forward movement, while the rearward movement thereof isprevented by the engagement of the pawls 66 with the teeth of the diskE54.

When it is desired to feed the motor rearwardly, the handle 33 may berotated in the position shown in dotted line in Fig. 12. In thisinstance, the cross pin 34 riding the cam 4S will again be positionedwithin two of the recesses 2, thus again causing the disengagement ofthe clutch member 46 with the worm gear 52 as shown in Fig. 6. The plate69 being driven by the cross pin 34 will assume the position shown inFig. l2 to permit the engagement of the pawls 6i with the teeth 65 oithe ring 6d and prevent the engagement of the pawls 65. In thisinstance, the rotation of the disk 64 and sprocket wheel 5i in acounterclockwise direction in Fig. l2 is prevented by the engagement ofthe pawls Si with the teeth S5, thus preventing the forward movement ofthe motor I6. During the rearward movement of the motor, the sprocketwheel 51 and disk 64 will rotate in a clockwise direction in Fig. l2,which rotation is not checked by the pawls El' since the latter willsimply ride the teeth of the disk Si without inter-- ference, thuspermitting a step by step rearward movement of the motor.

When it is desired to manually feed the motor I6 toward or away from theWork, the handle 33 may simply be positioned as shown in Fig. 10, thuscausing the reengagement of the clutch member i6 with the worm gear 56as shown in Fig. 5, and positioning the plate B9 as shown in Fig. 10 tomaintain the pawls E35 and 61 out of engagement with the teeth 65 of thedisk 69.

When the feeding mechanism is automatically operated, it will beunderstood that the shell 22 and motor i5 are fed toward or away fromthe work in the manner speciiied in connection with the manual operationof the mechanism, the motor moving in the same direction as the shellbut at a double rate of speed.

During the operation cf the drilling motor I3, the jars of the lattertransmitted to the chain 82 which passes over the sprocket wheel 5l,will be greatly cushioned by the rubber buffer 80 mounted within theapertured lug i3, thus protecting the chain against sudden jars whichmay cause the breakage thereof, as well as eliminating excessivevibrations in the mechanism associated with the sprocket wheel 5l.

Although the foregoing description is necessarily of a detailedcharacter, in order to completely set forth the invention, it is to beunderstood that various rearrangements of parts and modification ofstructural detail may be resorted to without departing from the scope orspirit of the invention as herein claimed.

I claim:

1. In a drilling apparatus, the combination with a stationary support,of a shell slidable thereon, of a drilling motor slidable on said shellhaving jars imparted thereto, a` mechanism associated with said motorand shell for imparting slidable movement thereto, means manually oper-'ated connectable with said mechanism for actuating the same, meansautomatically operated 'by the jars of said motor connectable with saidmechanism for actuating the same, and means for selectively connectingsaid manually or automatically operated means with said mechanism.

2. In a drilling apparatus, th-e combination with a stationary support,of a shell slidable thereon, of a drilling motor slidable on said shellhaving jars imparted thereto, a mechanism associated with said motor andshell for imparting slidable movement thereto, said mechanism beingnormally automatically operated by the jars of said motor, manuallyoperable means connectable with said mechanism for actuating the sameindependently of said jars, and means for connecting said manuallyoperable means with said mechanism and simultaneously rendering theautomatic operation thereof ineffective.

3. In a drilling apparatus, the combination with a stationary support, ashell slidable thereon, a drilling motor slidable on said shell havingjars imparted thereto, a sprocket wheel carried by said shell meshingwith a chain connected to said support and motor, a jar resistingmechanism and a manually operable rotation mechanism connectable withsaid sprocket wheel for either causing a step by step slidable movementof said motor and shell due to the jars of said motor or for impartingcontinuous slidable movement to said motor and shell, and means forselectively connecting either of said mechanisms to said sprocket wheel.

4. In a drilling apparatus, the combination with a stationary support, ashell slidable thereon, a drilling motor slidable on said shell havingjars imparted thereto, a mechanism associated with said motor and shellincluding movement transmitting means for transmitting continuousslidable movement to said motor and shell and movement checking meansfor checking the jars of said motor in one direction and thereby causingastep by step slidable movement of said motor and shell in the otherdirection, and means for selectively and operatively connecting saidmovement transmitting or checking means with said mechanism.

5. In a drilling apparatus, the combination with a support, of a shellslidabie thereon, of a drilling motor slidable on said shell, of afeeding mechanism associated with said motor and shell for effecting theslidable movement of said motor at a faster rate of speed than that ofsaid shell, manually operable means and means automatically operable bythe jars of said motor connectable with said mechanism for actuating thesame, and means for selectively connecting said manually operable orsaid automatically operable means with said mechanism.

6. In a drilling apparatus, the combination with a support, of a shellslidable thereon, of a drilling motor slidable on said shell, of afeeding mechanism associated with said motor and shell for effecting theslidable movement thereof at a greater rate of speed for said motor thanfor said shell, manually operated means and power operated meansconnectable with said feeding mechanism for actuating the same, andunitary means for selectively connecting either of said operated meanswith said mechanism.

7. In a drilling apparatus, the combination with a support, of a shellslidable on the support, of a motor slidable on the shell having apiston reciprocable therein imparting jars thereto tending to move themotor back and forth relative to the support, means utilizing the jarsoi the motor for eiecting a step by step movement thereof in onedirection including a sprocket Wheel rotatably mounted on the shell neareach end thereof, a chain meshing with said Wheels and connected to thesupport and motor for movement with the latter normally resulting in theoscillatory movement o1' the wheels, and a mechanism carried by theshell including stop means associated with one of said wheels forselectively controlling the direction of rotation thereof to enable astep by step movement of said chain and consequently of said motor inone or the other direction.

JOHN C. CURTIS.

